living legend
The world’s first submarine emerged in a moment of dire need within a divided nation. The Civil War split the United States into unequal parts, and industry in the North outpaced the South. This conflict is often viewed as the first true clash of the industrial age, where factories and technology directly influenced battlefield outcomes. The Union controlled the seas and had the advantage in most arenas, including naval power, while the Confederacy hoped to fight back with secret weapons and stealthy operations.
As part of the Anaconda plan, Northern navies blockaded southern ports, aiming to cut off supplies and cripple Confederate ambitions. The Southern fleet found it hard to challenge Union ships in direct battle, especially as the Union began deploying the era’s newest warships, the battleships. Facing superior forces, the Confederates clung to a bold idea: submarines that could operate unseen and strike at the heart of the fleet from below.
For generations, sailors and engineers debated this possibility. Legend even claimed that the first submariner was Alexander the Great, who supposedly used a diving bell during the siege of Tire. Historians dismiss that tale, though it hints at ancient curiosity about underwater warfare.
The first true submarine was built in 1620 by Dutch inventor Cornelius Drebbel, who worked under English commission. Its hull was a wooden frame clad in leather, and later models moved with oars as the crew guided them through water. The craft carried two devices far ahead of its time: a mercury barometer to measure depth and a chemical oxygen source powered by nitrate. Despite a series of Thames River trials, the Admiralty showed little interest. The king and a small circle of scientists remained impressed—Johannes Kepler even speculated that if Drebbel’s boat could move on its own, it would rival the splendor of Apollo in his eyes.
Under water and by candlelight
During the American Civil War, Confederate engineer Horace Hunley undertook the challenge of converting a survey ship into a war machine. The initial American Diver prototype proved slow and failed to enter combat, sinking in bad conditions before action could begin. The successor, designed with lessons learned, was named after its inventor, HL Hunley.
That vessel bore many features of modern submarines. Its 12‑meter hull was built from steel and used ballast tanks to submerge, flooded through valves and emptied by hand pumps. A propeller at the stern steered the craft, guided by a rudder. Two critical questions arose: how to turn the screw and where to mount a weapon. For the first mission, the crew briefly considered steam or an electric engine, but ultimately went with a simpler solution. Seven oarsmen sat along the length of the boat and powered a hand-cranked shaft, moving toward the engine. An eighth crew member acted as helmsman. The rowers had to stay close, without standing or shifting position, to maintain control.
Armed options were limited in 19th‑century naval warfare. Skirmishes and boarding actions were common, but neither suited a small underwater craft. Hunley instead used a remote torpedo concept. The device resembled a naval mine attached to a six‑meter beam with a wire fuse that could strike the target from beneath. It was meant to be detonated against the hull of a ship while submerged.
Hunley differed from Drebbel’s design in important ways. It was not fully submerged; a small cabin with windows and a ventilation pipe remained above the water for observation. There was no oxygen regeneration system, though a mercury barometer still tracked depth. Lighting came from a single candle, the only source aboard. Horace Hunley did not survive the trials, dying with his crew on October 15, 1863.
First and last fight
The Confederate Navy repaired Hunley and activated it for its first combat on February 17, 1864. The target was the screw sloop USS Housatonic, blockading Charleston, South Carolina. The Housatonic displaced about 1,240 tons and carried several large guns; a successful strike against it could prove devastating if the submarine failed to remain hidden.
The seven sailors aboard Hunley were commanded by Infantry Lieutenant George Dixon, a figure wrapped in legend. His partner in superstition was Queenie Bennett, who gave him a gold coin for luck and asked that it stay close. Dixon had already endured a gunshot wound at Shiloh in 1862, which left him with a lasting limp. A physician later noted that the coin absorbed much of the impact, sparing his leg from amputation.
As dusk settled, Hunley closed in on the Housatonic. The sloop spotted the threat, but it was too late to turn away. The submarine moved beneath the hull and disabled the ship’s main guns. Small arms fire filled the air, yet could not halt the attack. Hunley routed the torpedo beneath the hull, severed the connection, and flipped over. Moments later, the explosion sent the sloop lurching toward the pier and sinking rapidly. Five Hunley sailors perished; the remainder were rescued by Union ships that arrived soon after.
Hunley did not survive the engagement, and the exact cause of its loss remains debated. Early theories blamed the explosion of its own torpedo, but witnesses reported pyrotechnic signals from the ship long after the battle. Archaeologists who located Hunley in the 1970s could not settle the question. Experts now consider damage from the blast or small‑arms fire from the Housatonic crew as plausible culprits. A gold coin recovered from Dixon’s remains bore the marks of a gunshot, lending credence to the cherished Southern legend.
The widespread use of submarines would accelerate in World War I and continue through World War II. A key turning point was the diesel‑electric hybrid system, allowing submarines to cruise on surface power and submerge for attacks. In both World Wars, German forces relied heavily on submarine fleets to disrupt British maritime trade, a strategy born from wartime necessity. Submarines reached their full potential with nuclear propulsion, enabling extended underwater endurance and transforming undersea warfare into a prolonged, stealthy operation where essential supplies on board—food and power—became the only limits to their reach.